GREEN campaigners last night claimed visitors to the National Eisteddfod are likely to have breathed record levels of health-damaging air.

And they've called for action to cut traffic on roads, one of the main causes of smog.

Holidaymakers heading for the Welsh hills may have found air quality worse than in the cities they left behind.

Yesterday, it was revealed two sites in Wales, which test for smog, showed Government health limits were broken every day last week as temperatures soared across the country.

Environmental pressure group Friends of the Earth reported Aston Hill, near Montgomery in mid Wales, and Cwmbran in South Wales were among 25 stations which saw smog levels exceeded for seven days in a row.

Friends of the Earth spokesman Neil Crumpton said: "When we have weather like last week, when it's hot with still air and there is high pressure, that is exactly the sort of weather that will lead to smog levels building up.

"This year's Eisteddfod site at Meifod was located about 20 miles from the Aston Hill monitoring station near Bishop's Castle.

"As ozone polluted air recorded at this and at other rural sites is likely to have covered large rural areas, the Meifod area may well have experienced ozone-ladened air which breached official health limits. People who tried to escape the heat of the cities for a breath of fresh air may well have been breathing just the opposite.

"The Government, the Welsh Assembly and local authorities must do more to tackle the source of the pollution by cutting the amount of traffic on our roads."

Pollution from cars and industry is blamed as the major cause of smog, which contains ozone - this causes coughing and choking, headaches, eye, nose and throat irritation and chest dis-comfort.

On the Eisteddfod field, dozens of people needed treatment for heat-related illnesses..

Two people were taken to hospital suffering from heart problems.

A spokeswoman for the Welsh Ambulance Service spokes-woman said none of those treated were believed to be suffering from breathing difficulties.

Mr Crumpton added: "This sort of pollution definitely affects asthma.

"That has been known for many years, but scientists are now starting to think it could be one of the things that causes asthma.

"Looking beyond asthmas, Government scientists estimate that pollution could be causing 12,000 premature deaths every year in the UK so it's certainly bad news."